[GHC] #13157: Opportunity to improve case-of-case

[GHC]

#13157: Opportunity to improve case-of-case
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        Reporter:  simonpj           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:  JoinPoints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by nickkuk):

 It seems to be fixed, namely, GHC-8.2.1 with "-ddump-simpl -O" gives

 {{{
 f = \ (@ t_a1TX) (g_ap0 :: t_a1TX -> Bool) (x_ap1 :: t_a1TX) ->
       case g_ap0 x_ap1 of { __DEFAULT -> GHC.Types.True }
 }}}

 I will try to add test.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13157#comment:2>
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